Azhar can complete a journey in 10 hours. He travels the first half of the journey at a speed of 21 km/hr. and the balance at 24 km/hr. Find the total distance in km?

Let time taken to travel the first half = x hr 

Then time taken to travel the second half = (10 - x) hr 

Distance covered in the the first half = 21x [because, distance = time*speed]

Distance covered in the the second half = 24(10 - x)

Distance covered in the the first half = Distance covered in the the second half

According to the question,

21x=24(10-x)

21x + 24x = 240

45x = 240

x = $$\frac{240}{45}=\frac{16}{3}$$

Total Distance = $$2\times\ 21\times\ \frac{16}{3}=224$$ = 224 Km.